- Who (patient vs. ventilator), and what triggers (elapsed time vs. patient
effort) the inspiration, and by what triggering mechanism? - What limits/controls (pressure or volume) the gas flow being delivered?
- How does the inspiration end (cycle)?
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Flow over time
- Triggering
Based on who/what initiates the delivered breath, one can choose a mandatory
mode, a support mode, or a combination of both. Below are the most common
modes based on the triggering mechanism.
Controlled mandatory ventilation (CMV): The ventilator delivers the set
mandatory breaths at equal intervals (based on a set respiratory rate) regardless of
the patient effort. The patient is not able to breath above the set respiratory rate
(RR).
Intermittent mandatory breath (IMV): Similar to CMV the ventilator delivers the
set mandatory breaths at equal intervals regardless of the patient effort. The
difference is that the patient is able to breath in between the mandatory breaths;